Enzymes are often described as following the two-step mechanism: E + S= ES (fast) ES → E + P (slow) where E = enzyme, S = substrate, ES = enzyme-substrate complex, and P = product. (a) If an enzyme follows this mechanism, what rate law is expected for the reaction? (b) Molecules that can bind to the active site of an enzyme but are not converted into product are called enzyme inhibitors. Write an additional elementary step to add into the preceding mechanism to account for the reaction of E with I, an inhibitor.

Enzymes are often described as following the two-step mechanism: E + S= ES (fast) ES → E + P (slow) where E = enzyme, S = substrate, ES = enzyme-substrate complex, and P = product. (a) If an enzyme follows this mechanism, what rate law is expected for the reaction? (b) Molecules that can bind to the active site of an enzyme but are not converted into product are called enzyme inhibitors. Write an additional elementary step to add into the preceding mechanism to account for the reaction of E with I, an inhibitor.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

Suppose the formation of nitrosyl chloride proceeds by the following mechanism: step elementary reaction rate constant NO(g) + Cl2(g) NOCI2(g) k1 1 2 |NOCI2(g) + N0(g) → 2 NOC1(g) k2 Suppose also k,»k,. That is, the first step is much faster than the second. Write the balanced chemical equation for the overall chemical reaction: Write the ? experimentally- observable rate law for the overall chemical reaction. rate = k | Note: your answer should not contain the concentrations of any intermediates. Express the rate constant k for the overall chemical reaction in terms of k1, k2, and (if necessary) the rate constants k-1 and k = 0 k-2 for the reverse of the two elementary reactions in the mechanism. Dlo X
1) Discuss the transition state(s) in reaction coordinate diagram in the context of ΔG. 2) If an enzyme deceases the activation energy, ΔG‡, by the quantity X, we learned that the forward rate constant is increased by multiplication with the factor eX/RT. Why does this simple fact demonstrate that small changes in activation energy give big changes in catalyzed rates? 7)Two people study the same enzyme. They get different Vmax in each experiment, but the same kcat. Why?
(4) Use the following experimental data to write the rate law and the rate constant for the reaction 2 NO (g) + O2 (g) = 2 NO2 (g) Experiment [NO] (M) [O2] (M) Initial rate (M/s) 1 0.0100 0.0100 0.711 x 10-2 2 0.0100 0.0400 2.84 x 10-2 3 0.0200 0.0100 2.84 x 10-2
The reaction O₂(g) + 2 NO(g) → 2 NO₂(g) was studied at a certain temperature with the following results: (a) What is the rate law for this reaction? O Ratek [0₂(9)] [NO(g)] O Ratek [0₂(9)]² [NO(g)] O Rate = k [0₂(9)] [NO(g)]² O Ratek [0₂(9)]² [NO(g)]² O Ratek [0₂(9)] [NO(g)]³ O Rate = k [O₂(g)]* [NO(g)] (b) What is the value of the rate constant? Experiment [0₂(9)] (M) 0.0235 0.0235 0.0470 0.0470 [NO(g)] (M) 0.0235 0.0470 0.0235 0.0470 Rate (M/S) 0.158 0.633 0.317 1.27 (c) What is the reaction rate when the concentration of O₂(g) is 0.0318 M and that of NO(g) is 0.0649 M if the temperature is the same as that used to obtain the data shown above?
Consider the following Potential Energy Diagram for a four-step reaction mechanism. (a) What is the overall balanced equation for the reaction? (b) Does this reaction have a catalyst? Explain how you know. (c) Which step in the above mechanism is the rate-determining step? (d) Is this reaction exothermic or endothermic? (e) The rate law equation was determined to be rate = k [NO2] [F2]. Is the proposed mechanism plausible?
A mechanism involving the following elementary reactions has been proposed: 2 X (g) → X2 (g) (fast) X2 (g) +Y(g) = XY(g)+X(g) (slow) (8a) What is the reaction intermediate in this mechanism? (8b) What overall rate law will this mechanism produce?
2. The reaction of peroxydisulfate ion (S₂O) with iodide ion (I) is |S₂O²¯(aq) + 31¯(aq) →→→ 2SO¾¯(aq) + Iz (aq) From the following data collected at a certain temperature, determine the (a) rate law, (b) overall order of the reaction and (c) calculate the rate constant (Show your complete solution and use the data from Experiment I) Experiment [S₂0²¯] (M) [I] (M) Initial Rate (M/s) 1 0.080 0.034 2.2 × 10-4 2 0.080 0.017 1.1 x 10-4 3 0.16 0.017 2.2 x 10-4 Answers: b). overall order of the reaction: second-order Note: answer for letter a will be provided by the student. c.) 8.1 x 102 /M.s
The enzyme urease catalyzes the reaction of urea, 1NH2CONH22, with water to produce carbon dioxide and ammonia. In water, without the enzyme, the reaction proceeds with a first-order rate constant of 4.15 * 10-5 s-1 at 100 °C. In the presence of the enzyme in water, the reaction proceeds with a rate constant of 3.4 * 104 s-1 at 21 °C. (a) Write out the balanced equation for the reaction catalyzed by urease.
Suppose that a certain biologically important reactionis quite slow at physiological temperature (37 °C) in theabsence of a catalyst. Assuming that the collision factorremains the same, by how much must an enzymelower the activation energy of the reaction to achieve a1 x 105-fold increase in the reaction rate?
None
Which of the following statements is true about collision theory? O The orientation factor, p, for most molecular collisions is greater than 1. O An increase in temperature causes an increase in reaction rate primarily because the greater average speed causes the molecules collide more often. O Each collision of reactant molecules results in a reaction occurring. O An increase in the concentration of the reactants causes an increase in reaction rate because the energy of the collisions increases. O In the elementary reaction A + B reactant doubles the overall collision frequency. → AB , doubling the concentration of a
Be sure to answer all parts. Acetone is one of the most important solvents in organic chemistry. It is used to dissolve everything from fats and waxes to airplane glue and nail polish. At high temperatures, it decomposes in a first- order process to methane and ketene (CH,=C=0). At 600°C, the rate constant is 8.7 x 103 s1. (a) What is the half-life of the reaction? Give your answer in scientific notation. x 10 (select) A (b) How long does it take for 42% of a sample of acetone to decompose? (c) How long does it take for 82% of a sample of acetone to decompose? Give your answer in scientific notation. x 10 (select) O S